Messages in this thread | | | Date | Mon, 06 Aug 2007 18:18:15 +0100 | From | Simon Arlott <> | Subject | Re: [PATCH] kexec: fix pci device initialization fail after kexec (2.6.23-rc2). (Related to e1000 doesn't resume properly from standby) |
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On 06/08/07 16:50, Joonwoo Park wrote: > 2007/8/6, Rafael J. Wysocki <rjw@sisk.pl>: >> On Monday, 6 August 2007 15:42, Joonwoo Park wrote: >> > Hi. >> > I think that the pci_set_power_state() has bug. >> > The specification says that some delays is required. >> >> And they are in place, AFAICS (from drivers/pci/pci.c): >> >> /* Mandatory power management transition delays */ >> /* see PCI PM 1.1 5.6.1 table 18 */ >> if (state == PCI_D3hot || dev->current_state == PCI_D3hot) >> msleep(pci_pm_d3_delay); >> else if (state == PCI_D2 || dev->current_state == PCI_D2) >> udelay(200); >> > > The problem is occurred when state is 'PCI_D0', so those codes can't cover it. > But pci pm specification 5.4.1 says that when programmed to D0 the > equivalent of a warm reset, delay for the duration of the D3hot to D0 > Uninitialized state > transition (10ms) to pci signal drivers remain disabled is required. > >> > Simon, please can I know whether it works to you? >> > It is seems to the things are related. >> > >> > Joonwoo Park. >> > >> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> > index 37c00f6..9f78064 100644 >> > --- a/drivers/pci/pci.c >> > +++ b/drivers/pci/pci.c >> > @@ -493,8 +493,14 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) >> > * restore at least the BARs so that the device will be >> > * accessible to its driver. >> > */ >> > - if (need_restore) >> > + if (need_restore) { >> > + /* The specification also says that "Must ensure that all of >> > + * its PCI signal drivers remain disabled for the duration of >> > + * the D3hot to D0 Uninitialized state transition". >> > + */ >> > + msleep(10); >> >> It's too late for the delay. >> > > How about this?
It doesn't fix it.
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 37c00f6..974dd04 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -471,6 +471,8 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) > msleep(pci_pm_d3_delay); > else if (state == PCI_D2 || dev->current_state == PCI_D2) > udelay(200); > + else if (state == PCI_D0) > + msleep(10); > > /* > * Give firmware a chance to be called, such as ACPI _PRx, _PSx > > >> > pci_restore_bars(dev); >> > + } >> > >> > return 0; >> > }
Your patches have spaces everywhere instead of tabs.
-- Simon Arlott
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